The Biological Services Core laboratory of the BDC provides support in six areas for the Program Project investigators. These operations are supervised by Dr. K. Haskins and are managed by Philip Pratt. The Biological Services Core lab contains a CryoMed Liquid Nitrogen Cryopreservation System, for freezing and storing cells and tissues, which will be used in projects 2,3,4 and 6. The Graphics section supplies all the researchers with photographic prints and transparencies, and with both free-hand and computer-generated graphs, charts and illustrations. A fully functional photographic dark room has just been completed at the BDC. Biological Services maintains the non-obese diabetic (NOD) mouse inbred breeding colony for use in Projects 2 through 6. The primary breeding line is housed under sterile conditions within one room of the BDC animal facility. A second room holds the stock NOD's and the breeding sublines. The diabetic status of each animal is routinely monitored and diabetic animals are maintained by insulin therapy. Three technical assistants within Biological Services routinely isolate (collagenase digestion and microscopic harvesting) and culture rat and mouse pancreatic islets for use by investigators in Project 2 and 3. Several part-time student workers routinely wash and sterilize glassware for Projects 1,2,3,4 and 6. Lastly, Biological Services contains the BDC histology/immunohistology section which is fully equipped to provide processing, embedding, cutting and staining of both paraffin-embedded and frozen tissues for all the Project's researchers.